Progesterone for menopause: what it does, what the data say, and who should skip it
If you take estrogen and still have a uterus, you need a second hormone alongside it. Micronized progesterone is one choice. It is chemically the same molecule your ovaries made, and an oral form is FDA-approved. This page explains how it protects the uterus, how it differs from synthetic progestins, and where the evidence is solid and where it is thin.
Information current as of November 10, 2026. Educational only. Confirm everything here with your own clinician before starting, stopping or changing any medication.
At a glance
Its main job
It keeps estrogen from overgrowing the uterine lining. Oral micronized progesterone is FDA-approved for that purpose.
Micronized, not synthetic
Progesterone matches your own hormone. Progestins such as medroxyprogesterone are altered molecules that act differently.
It can make you sleepy
Taken at bedtime, it often causes drowsiness. Some women sleep better. Some feel foggy the next morning.
Check for peanuts
The oral capsule is made with peanut oil, so it is not for women with a peanut allergy.
No uterus, no need
After a hysterectomy there is no lining to protect, so most women take estrogen alone.
The basics
Micronized progesterone versus synthetic progestins
Doctors use the word progestogen for any medicine that acts like progesterone. That group has two branches. Micronized progesterone is the natural hormone, ground into very fine particles so the body can absorb it. Progestins are synthetic. They are built to resemble progesterone but have a different structure, and they can act on other receptors too. Medroxyprogesterone acetate and norethindrone are common examples.
The oral capsule sold as Prometrium is FDA-approved to prevent overgrowth of the uterine lining in postmenopausal women who have a uterus and are taking estrogen. It is also approved for secondary amenorrhea, which means periods that stopped for reasons other than pregnancy or menopause. The label names conjugated estrogen tablets as the studied partner. Doctors commonly pair it with estradiol. That pairing is standard practice, but it goes past the exact wording of the label.
You will see the word bioidentical used for progesterone. It is accurate as a description of the molecule. It does not tell you whether a given product has been tested, and we come back to that below.
How it works
How progesterone protects the uterine lining
Estrogen makes the lining of the uterus grow. Progesterone tells it to stop growing and to mature, and then to shed. Without that signal, the lining can overgrow and sometimes turn cancerous. That is why a woman with a uterus on estrogen needs a progestogen. Our estradiol page covers the estrogen side.
The PEPI trial compared regimens in about 600 postmenopausal women over three years. Women on estrogen alone often developed hyperplasia, which is abnormal thickening of the lining. Women who took estrogen with 200 mg of micronized progesterone for the first 12 days of each cycle had rates similar to placebo. Women who developed hyperplasia and were then treated with a progestin saw it return to normal in 34 of 36 cases.
The oral label dose for this purpose is 200 mg at bedtime for 12 days of each 28-day cycle, taken with daily estrogen. Many women have a light bleed after the last dose. Some doctors use a daily lower dose instead, which avoids the monthly bleed. An FDA-approved capsule that combines estradiol with progesterone takes that daily approach in one pill. Your doctor will explain which pattern fits you.
Beyond the uterus
Sleep, drowsiness and hot flashes
Progesterone breaks down into compounds that act on the same brain receptors as some sleep medicines. That is why the label warns about drowsiness and dizziness, and why it says to take the capsule at bedtime and to be careful driving.
A small crossover study gave 10 postmenopausal women 300 mg of micronized progesterone for 21 days. Sleep recordings showed less time awake during the night, and daytime thinking tests did not change. Ten women is a very small sample. A larger trial of 133 women found that 300 mg at bedtime reduced hot flash and night sweat scores more than placebo over 12 weeks, though placebo also helped.
Neither sleep nor hot flashes is an FDA-approved use of progesterone, so using it for them is off-label. Some women feel calmer and sleep deeper. Others feel groggy or low the next day, and for them the dose may be lowered or the route changed. Individual results vary.
The evidence
What we know about breast cancer risk
This is the question that matters most to many women, and the honest answer is that the data are good but incomplete.
In the Women’s Health Initiative, the combined arm raised breast cancer risk. It used medroxyprogesterone acetate, a synthetic progestin. After more than 20 years, women assigned to estrogen plus that progestin had a hazard ratio of 1.28 for breast cancer. That trial cannot tell us about micronized progesterone, because nobody in it took any.
The best human data on micronized progesterone come from the French E3N cohort. In its 2005 report, women using estrogen with synthetic progestins had a relative risk of 1.4 compared with non-users. Women using estrogen with micronized progesterone had a relative risk of 0.9, and its range included no increase. A 2008 analysis from the same cohort found that risk rose with longer use of estrogen plus progesterone for lobular and some receptor subtypes. An international expert panel reviewed the literature in 2018 and concluded that estrogen with micronized progesterone did not raise breast cancer risk for up to five years, with limited evidence beyond five years.
The limits of this evidence
E3N is an observational study of French women, and most of them used a particular route and dose. Observational data can mislead. No randomized trial has compared micronized progesterone with a synthetic progestin for breast cancer. Any combined hormone therapy needs breast cancer risk counseling, whichever progestogen is used.
Safety
Who should not take progesterone, and the peanut oil issue
The Prometrium label lists these as contraindications.
- An allergy to peanuts, because the capsules contain peanut oil
- Any hypersensitivity to the other ingredients
- Vaginal bleeding that has not been explained
- Known, suspected or past breast cancer
- A current blood clot in the leg or lung, or a history of one
- A current or past heart attack or stroke
- Known liver disease
The peanut oil is stated in the label itself. If you have a peanut allergy, tell us before any prescription is written, and read the ingredient list of any product you are handed. Other forms of progesterone, including vaginal inserts and compounded products, have their own ingredient lists, so the same check applies.
Other forms
Vaginal and compounded progesterone
Vaginal progesterone gels and inserts are FDA-approved for other purposes, mainly in fertility care. Using them to protect the uterus during menopausal estrogen therapy is off-label. Some studies have used vaginal gel in this role, including the ELITE trial, and the expert panel that reviewed breast data called it off-label use. Off-label means a doctor may choose it based on judgment, but the FDA has not approved it for that purpose.
Compounded progesterone is a different matter. Troches, creams and custom capsules are made by a pharmacy for one patient. They are not FDA-approved, and the FDA does not evaluate them for safety, effectiveness or quality. The American College of Obstetricians and Gynecologists advises against routine use of compounded bioidentical hormone therapy when approved products exist. Blood levels from skin creams vary a lot between women, and protection of the uterine lining with a cream has not been established. A compounded product is not the same as the brand-name capsule, and we do not treat it as if it were.
When it is not needed
When you do not need a progestogen
A progestogen protects the lining of the uterus. If your uterus has been removed, there is no lining, and estrogen is usually taken alone. The Women’s Health Initiative estrogen-alone trial enrolled women who had had a hysterectomy for this reason.
Low-dose vaginal estrogen used for local symptoms is generally taken without a progestogen, because very little reaches the bloodstream. How long that stays true is still being refined, and any unexpected bleeding should be checked. If you are unsure whether you need progesterone, ask your doctor to confirm what surgery you had, because “partial” and “supracervical” procedures can leave tissue behind.
Follow-up
Monitoring
There is no lab number that tells us whether progesterone is working on your uterus. We watch what you tell us and what your history shows.
- Your bleeding pattern. A light, planned bleed after a cyclic course can be normal. Heavy, prolonged or unscheduled bleeding needs a workup.
- Daytime sleepiness, dizziness or low mood after starting
- Blood pressure and a refreshed view of your clot and cancer history
- Up-to-date breast cancer screening
- A yearly review of whether you still need the dose you are on
Call for care right away if you have sudden vision changes, chest pain, a swollen painful leg, severe headache or trouble breathing.
Summit’s role
How Summit uses progesterone
Summit Metabolic Health is telehealth-only. Dr. Miranda reviews your history, symptoms and labs first, then decides whether hormone therapy fits. For women with a uterus who take estrogen, progesterone or another progestogen is part of that plan. We prefer FDA-approved products where one fits. If a compounded product is chosen, it comes from an independent state-licensed pharmacy, and it is not FDA-approved or evaluated by the FDA.
Our full approach to menopause care is in our hormone replacement therapy guide. Fees are on the pricing page. Not every applicant is a candidate for hormone therapy, and the physician makes that call.
Common questions
Questions people ask
Is progesterone the same as progestin?
No. Micronized progesterone is the same molecule your ovaries made. Progestins are synthetic and have a different structure. They protect the uterine lining too, but they behave differently in the body, and the breast cancer and clot data differ between them.
Will progesterone help me sleep?
It can. A small study found less time awake at night, and the label warns about drowsiness. Sleep is not an FDA-approved use, though, so this is off-label, and some women feel groggy the next day. Do not drive until you know how it affects you.
Does progesterone raise my breast cancer risk?
The evidence is mixed. A large French cohort found no increase with micronized progesterone for up to five years, while a synthetic progestin was linked to higher risk. That is observational data, and evidence beyond five years is limited. Counseling on breast risk applies to any combined therapy.
I am allergic to peanuts. Can I take it?
The oral capsule is made with peanut oil and the label lists peanut allergy as a contraindication. Tell your doctor before a prescription is written, and ask about options that do not use peanut oil.
Do I need progesterone with a patch or gel?
If you have a uterus, yes. The skin route changes how estrogen is absorbed, but it does not remove the need to protect the lining. See our estradiol page for the full picture.
Sources
Where this comes from
All retrieved November 10, 2026.
- The PEPI Trial. Effects of hormone replacement therapy on endometrial histology in postmenopausal women. JAMA 1996 https://pubmed.ncbi.nlm.nih.gov/8569016/
- Fournier A et al. Breast cancer risk in relation to different types of hormone replacement therapy in the E3N-EPIC cohort. Int J Cancer 2005 https://pubmed.ncbi.nlm.nih.gov/15551359/
- Fournier A et al. Use of different postmenopausal hormone therapies and risk of histology- and hormone receptor-defined invasive breast cancer. J Clin Oncol 2008 https://pubmed.ncbi.nlm.nih.gov/18323549/
- Stute P et al. The impact of micronized progesterone on breast cancer risk: a systematic review. Climacteric 2018 https://pubmed.ncbi.nlm.nih.gov/29384406/
- Chlebowski RT et al. Association of menopausal hormone therapy with breast cancer incidence and mortality during long-term follow-up of the WHI trials. JAMA 2020 https://pubmed.ncbi.nlm.nih.gov/32721007/
- Schussler P et al. Progesterone reduces wakefulness in sleep EEG and has no effect on cognition in healthy postmenopausal women. Psychoneuroendocrinology 2008 https://pubmed.ncbi.nlm.nih.gov/18676087/
- Hitchcock CL, Prior JC. Oral micronized progesterone for vasomotor symptoms: a placebo-controlled randomized trial. Menopause 2012 https://pubmed.ncbi.nlm.nih.gov/22453200/
- Hodis HN et al. Vascular effects of early versus late postmenopausal treatment with estradiol (ELITE). N Engl J Med 2016 https://pubmed.ncbi.nlm.nih.gov/27028912/
- ACOG Clinical Consensus No. 6. Compounded bioidentical menopausal hormone therapy. Obstet Gynecol 2023 https://pubmed.ncbi.nlm.nih.gov/37856860/
- Prometrium (progesterone) capsules prescribing information, DailyMed https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=1cf237ff-c4f8-4faa-a7aa-77599c856889
Confirm with your provider. This page is general education, not medical advice, and it does not diagnose or treat anything. Every medication carries risks and is not right for everyone. Medication is prescribed only after a physician evaluation determines it is appropriate for you. Individual results vary and no outcome is guaranteed. Information current as of November 10, 2026.
Next step
Talk to a physician about hormone therapy
Dr. Miranda reviews every application personally. If hormone therapy is a fit, you will see a plan that names the product, the route and the follow-up. If it is not, he will tell you why.